DADGAD Tuner Online — Modal Celtic Tuning

DADGAD is an alternate guitar tuning, D A D G A D from low to high, whose open strings sound neither major nor minor. The sixth, second and first strings drop a whole tone from standard; the fifth, fourth and third keep their pitches. Its suspended modal sound is common in Celtic and folk guitar.

How to use it

1. Start from standard tuning. Three strings move and three stay, so the unchanged strings are your reference while you work.
2. Lower the sixth string from E2 to D2 (73.42 Hz). A whole tone down.
3. Lower the second string from B3 to A3 (220.00 Hz). A whole tone down. This is the string most players find slowest to settle.
4. Lower the first string from E4 to D4 (293.66 Hz). A whole tone down.
5. Leave the fifth, fourth and third strings alone. They stay at A2 (110.00 Hz), D3 (146.83 Hz) and G3 (196.00 Hz).
6. Strum the open strings. You should hear an open, suspended D sound: a D chord with no third in it. If it sounds like a normal major chord, the second or first string has not dropped far enough.
7. Re-check the second and first strings after a minute. They are the thinnest strings in the set and the ones you moved most, so they drift first.

Two ear checks confirm the tuning without the display: the open fourth string (D3) should sound an octave above the sixth (D2), and the open second string (A3) should sound an octave above the fifth (A2).

DADGAD string frequencies

String	Note	Frequency (A4 = 440 Hz)
6th	D2	73.42 Hz
5th	A2	110.00 Hz
4th	D3	146.83 Hz
3rd	G3	196.00 Hz
2nd	A3	220.00 Hz
1st	D4	293.66 Hz

Modal neutrality

The open strings are D, A, D, G, A and D. Those notes give the root D, the fifth A and the fourth G, but no third. A chord with no third is neither major nor minor, which is exactly what makes DADGAD useful for modal music:

• Both thirds are a finger away. Add F# and the sound is D major; add F and it is D minor. The tuning does not commit you until you fret the note.
• Drones work under everything. The open D and A strings can ring through chord changes without clashing, because they are the root and fifth of the home key.
• The mode is decided by what you fret. The open strings give you the root, the fourth and the fifth but no third, so G and A alone do not settle the mode. Add F# and the sound is major, add F and it is minor; from there, B natural gives D Dorian and C natural gives D Mixolydian — the raised sixth and the lowered seventh are the notes each mode is built around.
• The open tuning is not a chord progression. Strumming all six strings gives an atmospheric Dsus4 sound rather than a functional I chord, so progressions are usually built around fretted shapes with the drones left ringing.

That modal quality is the practical difference between DADGAD and open D. Open D has the major third built into the tuning, so it always sounds major; DADGAD leaves the third out and stays flexible.

Learning the shapes

The fifth, fourth and third strings are unchanged from standard tuning, so a lot of what you already know still works in the middle of the neck. The second and first strings are the ones to relearn:

• Barre chords do not behave. A standard major barre shape depends on the second and first strings being tuned to B and E. In DADGAD those strings are a whole tone lower, so the same shape produces a different chord.
• The top two strings are a whole tone down. Anything you play above the third string has moved. Scale patterns, melody lines and double stops on the first two strings need to be re-fingered or transposed.
• Start with drones, not chords. Picking melodies over ringing open bass strings is the fastest way to make music in DADGAD and the reason the tuning is associated with Celtic accompaniment.
• Use a capo to change key without relearning. Capoing at the second fret moves the whole tuning up a tone, so the same shapes produce E-centred music; players who want a different key normally move the capo rather than retune.

Celtic and folk players use DADGAD for accompaniment because the drones imitate the continuous bass of pipes and the modal openness fits tunes that are not built on functional harmony. Rock players use it for the same reason at higher volume: the suspended open strings sound neither happy nor sad, which suits atmospheric writing.

Accuracy and limits

• A and D each repeat across the tuning. D is on the sixth, fourth and first strings (D2, D3, D4) and A on the fifth and second (A2, A3). The second string is the one to watch: its A3 shares a note name with the open fifth, so a ringing fifth string can pull the display an octave down. Mute and compare against the card for the string you played.
• Three strings never move, and they are your reference. The fifth, fourth and third strings keep their standard pitches, so if they read correctly before you start they should read correctly at the end. A wrong reading there points to the microphone hearing another string, not to a drifted one.
• The two dropped treble strings are thin and settle slowly. The second and first strings lose a whole tone of tension, so they speak quietly and drift first after a retune. Pluck them cleanly and check them again after a minute.
• A capo rewrites every target. With a capo fitted, the strings sound a tone or more above the pitches printed on the cards, so the strings you are matching are not the ones the preset names. Tune with the capo off, then fit it and expect the reading to sit sharp by design.
• The dropped sixth string is the microphone’s weak point. D2 at 73.42 Hz sits in the region where small laptop and phone microphones are least sensitive (typically below ~100 Hz). Pluck it firmly and let it settle rather than judging the first frame.

Safety

• All three changes lower pitch. The sixth, second and first strings drop a whole tone, so reaching DADGAD removes tension from the neck rather than adding it.
• Returning to standard is the careful part. Raise the second and first strings a whole tone each, and the sixth a whole tone. Work in small increments and stop at the target.
• The first string is the one to watch. It is the thinnest string on the guitar, and a whole-tone rise from D4 to E4 is where rushed tuning breaks it. Turn the peg slowly near pitch.
• Ease a binding string free. If the first or second string pings or sticks while you tune, it is catching in the nut slot. Free it gently rather than forcing the peg, which can snap the string.
• Do not detune under a capo. Capoing raises pitch by design. Slackening the strings to bring the capoed pitch back down defeats the tuning and leaves the guitar unstable.
• If the low D buzzes, check the setup. DADGAD’s low D can rattle on a guitar with low action. Heavier strings or an action adjustment fix it; tuning sharp does not.